The most important thing you need to remember is your Ad Server is a Windows based computer and needs to have the display settings match the resolution you select in the desktop control panel.
Step 1 Set windows resolution and in this case it’s 1920 x 1080
Step 2 Set the same resolution in the Desktop Control Panel for the system you’re working with.
Setting up a custom screen size to match your TV
So many TVs and Monitors are different and have higher and higher resolutions so I added a custom sizing routine to help with that directly in the software itself. See more here